1. The output of
urobilin is increased in experimental trypanosome
anemia presumably as a result of the increased blood destruction. 2. The administration of
salvarsan (
arsenobenzol) during the anemic period, if it checks the blood destruction, reduces the
urobilin elimination, but this result does not follow unless the blood picture improves. 3. Following
splenectomy in the normal dog an increase in the
urobilin elimination of varying degree occurs, the significance of which is doubtful. 4.
Splenectomy during the period of
anemia does not cause a decrease in
urobilin elimination. The experiments support the view that the elimination of
urobilin may be considered as an index of blood destruction, but they do not explain the decrease in the elimination occurring in man in certain forms of
hemolytic anemia following
splenectomy.